In the related art, a printer, such as a receipt printer, a portable printer, and a label printer for printing a label, which may be mounted on or connected to a point of sales (POS) terminal that processes a sales registration of a purchased commodity, often uses a thermal printer having a line thermal head, which transfers heat using the line thermal head while conveying a thermal paper (hereinafter, referred to as “paper”) to develop color on the thermal paper. These printers perform printing by increasing a conveying speed of a paper at high speed as much as possible.
If a character, a number, a symbol, or the like (hereinafter, collectively referred to as “characters”) is printed, by the thermal printer, on the paper, the character generally can be formed accurately and read even if high-speed printing is performed. However, if a code such as a bar code and a two-dimensional code and a pattern such as a logo and a coupon (hereinafter, code and pattern are collectively referred to as “figure”) are printed and high-speed printing is performed, “tailing” phenomenon may occur in which unintentional printing is caused due to residual heat accumulated in the head. If such a phenomenon occurs, for example, the printed code including the tailing may not be read correctly, or a gradation of the figure may not be properly printed out.
Therefore, if printing of an image including the figure is performed, printing is no longer performed at a high speed, and instead performed at a low speed.
However, if printing of an image including a figure and characters is performed and the figure and characters are simultaneously printed by the line thermal head, the conveying speed is set to be low because of the presence of the figure. Therefore, for simultaneous printing of the figure and characters, electric power consumed for printing of the character is larger than necessary.